Datasheet

 1997-2013 Microchip Technology Inc. DS30234E-page 135
PIC16C6X
FIGURE 13-14: EXTERNAL POWER-ON
RESET CIRCUIT (FOR SLOW
V
DD POWER-UP)
Note 1: External Power-on Reset circuit is required
only if V
DD power-up slope is too slow. The
diode D helps discharge the capacitor
quickly when V
DD powers down.
2: R < 40 k is recommended to make sure
that voltage drop across R does not violate
the devices electrical specifications.
3: R1 = 100 to 1 k will limit any current
flowing into MCLR
from external capacitor
C in the event of MCLR
/VPP pin break-
down due to Electrostatic Discharge
(ESD) or Electrostatic Overstress (EOS).
C
R1
R
D
V
DD
MCLR
PIC16CXX
FIGURE 13-15: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 1
FIGURE 13-16: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 2
Note 1: This circuit will activate reset when VDD
goes below (Vz + 0.7V) where Vz = Zener
voltage.
2: Internal brown-out detection on the
PIC16C62A/R62/63/R63/64A/R64/65A/
R65/66/67 should be disabled when using
this circuit.
3: Resistors should be adjusted for the
characteristics of the transistors.
VDD
33k
10k
40k
V
DD
MCLR
PIC16CXX
Note 1: This brown-out circuit is less expensive,
albeit less accurate. Transistor Q1 turns
off when V
DD is below a certain level such
that:
2: Internal brown-out detection on the
PIC16C62A/R62/63/R63/64A/R64/65A/
R65/66/67 should be disabled when using
this circuit.
3: Resistors should be adjusted for the
characteristics of the transistors.
V
DD •
R1
R1 + R2
= 0.7V
VDD
R2
40k
V
DD
MCLR
PIC16CXX
R1
Q1